U.S. patent application number 16/162349 was filed with the patent office on 2020-04-16 for liquid crystal display device.
The applicant listed for this patent is Panasonic Liquid Crystal Display Co., Ltd.. Invention is credited to Satoshi HIROTSUNE, Katsuji TANAKA.
Application Number | 20200118502 16/162349 |
Document ID | / |
Family ID | 70159447 |
Filed Date | 2020-04-16 |
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United States Patent
Application |
20200118502 |
Kind Code |
A1 |
HIROTSUNE; Satoshi ; et
al. |
April 16, 2020 |
LIQUID CRYSTAL DISPLAY DEVICE
Abstract
A liquid crystal display device is disclosed utilizing two or
more display panels stacked on top of each other. In a dual panel
configuration, the first display panel may be comprised of color
pixels and the second display panel may be comprised of contrast
pixels. The color pixel in the first display panel has a
corresponding contrast pixel in the second display panel wherein
said contrast pixel is larger in terms of length and in size than
the corresponding color pixel. The liquid crystal display device
may also switch to a mode that uses an expansion method of contrast
pixels to reduce image displacement. Further disclosed is a
configuration where the relative position of the first display
panel and the second display panel may be adjusted to align the
corresponding color and contrast pixels when viewing the display in
oblique angles.
Inventors: |
HIROTSUNE; Satoshi; (Hyogo,
JP) ; TANAKA; Katsuji; (Hyogo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Panasonic Liquid Crystal Display Co., Ltd. |
Hyogo |
|
JP |
|
|
Family ID: |
70159447 |
Appl. No.: |
16/162349 |
Filed: |
October 16, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G09G 2320/028 20130101;
G09G 2360/04 20130101; G09G 2300/0491 20130101; G02F 1/136286
20130101; G09G 3/3607 20130101; G02F 1/13338 20130101; G09G
2300/023 20130101; G09G 2320/0261 20130101; G09G 2320/066 20130101;
G09G 3/3426 20130101; G02F 1/133602 20130101; G09G 3/3648
20130101 |
International
Class: |
G09G 3/36 20060101
G09G003/36; G02F 1/1362 20060101 G02F001/1362; G02F 1/1335 20060101
G02F001/1335; G02F 1/1333 20060101 G02F001/1333 |
Claims
1. A liquid crystal display (LCD) device comprising: a first
display panel having a plurality of pixels; and a second display
panel having a plurality of pixels, the first and the second
display panels being positioned in a stacked configuration in plan
view, wherein a size of a pixel from the plurality of pixels in the
second display panel is larger than a size of a pixel from the
plurality of pixels in the first display panel.
2. The LCD device according to claim 1, further comprising a
backlight, wherein the second display panel is located between the
first display panel and the backlight.
3. The LCD device according to claim 1, wherein the pixel from the
plurality of pixels in the first display panel comprises a
plurality of color sub-pixels.
4. The LCD device according to claim 1, wherein the pixel from the
plurality of pixels in the second display panel comprises a
contrast pixel.
5. The LCD device according to claim 1, wherein the first display
panel has the same number of pixels as the second display
panel.
6. The LCD device according to claim 1, further comprising: a
plurality of gate lines extending in a first direction; and a
plurality of data lines extending in a second direction, wherein a
length in the first direction of the pixel from the plurality of
pixels in the second display panel is longer than a length in the
first direction of the pixel from the plurality of pixels in the
first display panel.
7. The LCD device according to claim 1, further comprising: a
plurality of gate lines extending in a first direction; and a
plurality of data lines extending in a second direction, wherein a
length in the second direction of the pixel from the plurality of
pixels in the second display panel is longer than a length in the
second direction of the pixel from the plurality of pixels in the
first display panel.
8. The LCD device according to claim 6, wherein the length in the
first direction of the pixel from the plurality of pixels in the
second display panel is within a range of 1.003 to 1.15 times
longer than the length in the first direction of the pixel from the
plurality of pixels in the first display panel.
9. The LCD device according to claim 7, wherein the length in the
second direction of the pixel from the plurality of pixels in the
second display panel is within a range of 1.003 to 1.15 times
longer than the length in the second direction of the pixel from
the plurality of pixels in the first display panel.
10. The LCD device according to claim 1, wherein an area of a
second display region in the second display panel is larger than an
area of a first display region in the first display panel.
11. The LCD device according to claim 10, wherein the area of the
second display region is within a range of 1.006 to 1.323 times
larger than the area of the first display region.
12. The LCD device according to claim 1, further comprising an
image processing unit configured to: receive an external input
image data; generate a color image data for the first display panel
based on the external input image data; and generate a contrast
image data for the second display panel based on the external input
image data, wherein the image processing unit switches to a first
mode or a second mode, the image processing unit generates a first
contrast image data in the first mode or a second contrast image
data in the second mode, and the image processing unit generates a
first image based on the first contrast image data and a second
image based on the second contrast image data, the second image
being more blurred than the first image.
13. The LCD device according to claim 12, further comprising a
control device configured to switch the image processing unit to
the first mode or the second mode.
14. The LCD device according to claim 13, further comprising a
sensing device that detects a position of a person viewing the LCD
device, wherein the control device switches the image processing
unit to the first mode or the second mode depending on the position
of the person.
15. The LCD device of claim 14, wherein the sensing device is a
camera.
16. An LCD device comprising: a first display panel having a
plurality of pixels; a second display panel having a plurality of
pixels, the first and the second display panels being positioned in
a stacked configuration in plan view; and an adjuster changing a
relative position between the first display panel and the second
display panel.
17. The LCD device according to claim 16, further comprising a
backlight, wherein the second display panel is located between the
first display panel and the backlight.
18. The LCD device according to claim 16, wherein the adjuster
changes the relative position in a plane parallel to a surface of
the first display panel.
19. The LCD device according to claim 18, further comprising a
plurality of gate lines extending in a first direction; and a
plurality of data lines extending in a second direction, wherein
the adjuster changes the relative position in the first
direction.
20. The LCD device according to claim 18, further comprising a
plurality of gate lines extending in a first direction; and a
plurality of data lines extending in a second direction, wherein
the adjuster changes the relative position in the second direction.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a liquid crystal display
device utilizing two or more liquid crystal display panels in a
stacked configuration.
BACKGROUND
[0002] Liquid crystal displays (LCDs) are nowadays ubiquitous
because of many advantages over other display systems such as a
cathode ray tube (CRT) display or plasma display. However, LCDs
have traditionally suffered in terms of contrast ratio.
[0003] One of the techniques for improving the contrast ratio of an
LCD device is by stacking LCD panels on top of each other. For
example, a prior art discloses a LCD device comprising of a first
display panel and a second display panel stacked on top of each
other (See, for example, U.S. Pat. No. 8,451,201). The first
display panel produces an image based on a first image data and the
second display panel produces an image based on a second image
data.
[0004] As illustrated in FIG. 1, with an LCD device 10 comprising
of a first display panel 100 and a second display panel 200 stacked
on top of each other, pixel 131.sub.x in the first display panel
100 aligns with its corresponding pixel 231.sub.x in the second
display panel 200 when viewed from a position 2 of a person 1 at a
distance H. However, because of a gap D, which may be due to the
components of the display panels as well as other components that
are positioned between them, the corresponding pixels 131.sub.y and
231.sub.y may not properly align when the LCD device 10 is viewed
by person 1 from position 2. Hence, a person viewing a display
device utilizing two or more display panels may experience poor
image quality caused by image displacement when viewing the display
device from an oblique angle.
[0005] To prevent image displacement, it is necessary to keep the
gap D as small as possible. However, the use of two or more LCD
panels makes image displacement an inherent problem of the
multi-display panel configuration because the gap D can only be
minimized but not totally removed due to the presence of other
components in the display device. The present disclosure describes
several techniques and methods to mitigate, if not entirely
eliminate, image displacement in LCD devices utilizing two or more
display panels in a stacked configuration.
SUMMARY
[0006] The present disclosure pertains to an LCD device comprising
of two or more display panels stacked on top of each other. In a
dual display panel set-up, the first display panel is comprised of
color pixels that filter color while the second display panel is
comprised of contrast pixels that filter the intensity of light. A
backlight unit positioned behind the second display panel provides
light to the display panels. Each color pixel in the first display
panel has a corresponding contrast pixel in the second display
panel. When the corresponding pixels are aligned, the LCD device
produces an image with high contrast ratio as compared to a single
panel configuration.
[0007] Each display panel may be composed of polarizers, a layer of
thin film transistors ("TFT"), spacers, and other components of a
typical LCD panel. A diffuser may be placed between the two display
panels. Each display panel includes a data line driving circuit, a
gate line driving circuit, and a timing controller. The driving
circuits switch the alignment of the liquid crystal modifying the
direction of incident light. A common electrode and a pixel
electrode are provided for each pixel or sub-pixel, applying an
electric field to the liquid crystal.
[0008] The LCD display includes an image processing unit with a
color image processor and a contrast image processor. The color
image processor generates color image data which controls the color
pixels in the first display panel. On the other hand, the contrast
image processor generates contrast image data which controls the
contrast pixels in the second display panel. Light coming from the
backlight unit forms an image when it passes through and is
filtered by pairs of corresponding color pixels and contrast
pixels.
[0009] When multiple LCD panels are positioned in a stacked
configuration, the gap between the LCD panels create an inherent
problem regarding the alignment of corresponding color pixels and
contrast pixels. In a dual LCD panel configuration, the color pixel
in the first display panel may not align with the corresponding
contrast pixel in the second display panel if the LCD device is
viewed at an oblique angle (See FIG. 1). Hence, the resulting image
displayed by the LCD device appears less sharp or a double image
may be formed. Such image displacement is not ideal because the
image quality produced by the LCD device is degraded and the image
may become unusable in applications that require viewing the
display from an oblique angle.
[0010] In an embodiment of the present disclosure, the problem
caused by the misalignment of the corresponding color pixels and
contrast pixels when viewed from an oblique angle is addressed by
utilizing larger size of pixels in one of the display panels. In
the LCD device comprising of the first display panel consisting of
color pixels and the second display panel consisting of contrast
pixels, said contrast pixels in the second display panel are larger
in size than the color pixels in the first display panel. In this
configuration, the length of a contrast pixel along a first
direction may be 1.003 to 1.150 times longer than the length of a
color pixel in the same direction. Similarly, the length of a
contrast pixel along a second direction perpendicular to the first
direction in a plane parallel to the display panels may likewise be
1.003 to 1.150 times longer than the length of a color pixel in the
same direction. In terms of the area of the pixels, the area of a
contrast pixel may be 1.006 to 1.323 times larger than the area of
a color pixel. Consequently, the area of the second display panel
containing the contrast pixels may be 1.006 to 1.323 times larger
than the area of the first display panel containing the color
pixels.
[0011] In another embodiment of the present disclosure, a control
device is introduced to switch the image processing into a first
mode or a second mode. Under the first mode, the LCD device is
viewed directly from the center (See FIG. 8A) while under the
second mode, the LCD device is viewed from the periphery (See FIG.
8B).
[0012] In the second mode, the contrast image data generated by the
image processing unit for the contrast pixels is modified using a
known expansion method. In the first mode, no or less expansion is
applied. The expansion method approximates the correct amount of
light provided to a color pixel by a contrast pixel which is not
necessarily the corresponding contrast pixel of the color pixel.
The expansion method employs averaging the brightness of a
corresponding contrast pixel in relation to the brightness of
neighboring contrast pixels. As a result, the image produced by the
second display panel is less sharp or more blurred than the image
produced by the first display panel. However, when the LCD device
is viewed from an oblique angle, image displacement is mitigated by
the expansion method.
[0013] The control device may be operated manually or it may
automatically switch from the first mode to the second mode or
vice-versa depending on the position of the person viewing the LCD
device as detected by a sensing device. The sensing device may be a
camera, a proximity sensor, or any device that allows the control
device to determine the approximate position of the person.
[0014] In another embodiment of the present disclosure, the
position of the first display panel may be changed relative to the
position of the second display panel or vice versa. The change in
relative position between the first display panel and the second
display panel may therefore reduce image displacement that causes
poor image quality. The change in the relative positions of the
display panels ensures alignment of the corresponding color pixels
in the first display panel and the contrast pixels in the second
display panel when viewed from a particular position. An adjuster
device may facilitate the change in the relative position of the
display panels. The adjuster device may be configured to change the
relative position of the first display panel and the second display
panel along the plane parallel to the display areas of the display
panels, or along the direction perpendicular to the said plane. The
adjuster device may be controlled manually or automatically by
employing an appropriate sensing device capable of determining the
approximate the location of the eyes of the person viewing the LCD
device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Both described and other features, aspects and advantages of
an LCD device in accordance with the embodiments of the present
disclosure will be better understood with reference to the
following drawings.
[0016] FIG. 1 is a schematic diagram illustrating the alignment of
the pixels of two display panels stacked on top of each other
according to a conventional LCD device;
[0017] FIG. 2 is a schematic exploded perspective view
schematically illustrating an LCD device and a person viewing the
said LCD device, according to exemplary embodiments of the present
disclosure;
[0018] FIG. 3 is a schematic cross-sectional view of the LCD device
of FIG. 2 according to the exemplary embodiments of the present
disclosure;
[0019] FIG. 4A is a schematic diagram of the color pixels of the
first display pane according to the exemplary embodiments of the
present disclosure;
[0020] FIG. 4B is a schematic diagram of the contrast pixels of the
second display panel according to the exemplary embodiments of the
present disclosure;
[0021] FIG. 5 illustrates the connections between the first and
second display panels and their respective driving circuits and
controllers of the LCD device according to the exemplary
embodiments of the present disclosure;
[0022] FIG. 6 is a schematic diagram of the components of an image
processing unit of the LCD device according to the exemplary
embodiments of the present disclosure;
[0023] FIG. 7 is a schematic diagram illustrating the alignment of
the pixels of the first and second display panels of the LCD device
of FIG. 2 according to the exemplary embodiments of the present
disclosure;
[0024] FIG. 8A is a perspective view schematically illustrating the
LCD device and a person viewing the said LCD device from the center
position;
[0025] FIG. 8B is a perspective view schematically illustrating the
LCD device and a person viewing the said LCD device from the
periphery position;
[0026] FIG. 9 is a perspective view schematically illustrating the
LCD device with a sensing device; and
[0027] FIG. 10 is a perspective view schematically illustrating the
LCD device with an adjuster device.
DETAILED DESCRIPTION
[0028] Embodiments of the present disclosure will be described with
reference to the drawings for a greater understanding of the
embodiments and so as to help explain the principles used in this
disclosure in order to guide person having ordinary skill in the
art.
[0029] The embodiments in the present disclosure will be presented
clearly and in reference to the drawings but in no case shall the
present disclosure be limited to these embodiments and drawings.
This disclosure herein may be implemented in ways that are not
described by the embodiments and drawings but are covered by the
present disclosure. The embodiments and drawings in this
application are meant to give a full and sufficient disclosure of
the invention but the scope of the invention must be defined in
respect to the claims appended to this application. Furthermore,
the drawings are not necessarily drawn to scale and may be
exaggerated for purposes of clarity of presentation. Similarly,
number labels are used such that similar reference numbers refer to
like or similar elements as used in the other drawings in this
specification.
[0030] The present disclosure pertains to an LCD device consisting
of multiple display panels. FIG. 2 is an exploded view of an LCD
device 10 comprising of a first display panel 100, having a display
area 111, and a second display panel 200, having a display area
211, stacked on top of each other, in accordance with an embodiment
of the present disclosure. The LCD device 10 displays an image that
is viewed from a distance H by a person 1 at a position 2, said
position 2 is the location of the eyes of person 1.
[0031] FIG. 3 shows cross-sectional view of the LCD device 10 in
accordance with an embodiment of the present disclosure. A
backlight unit 9 positioned behind the second display panel 200
provides light to the display panels. The first display panel 100
is comprised of a plurality of color pixels 131 that filter color
and the second display panel 200 is comprised of a plurality of
contrast pixels 231 that filter the intensity of light.
[0032] As shown in FIG. 3, each display panel 100, 200 is composed
of layered components. Each display panel 100, 200 includes an
upper substrate 120, 220 and a lower substrate 180, 280 positioned
with the planes parallel to each other and with liquid crystal 150,
250 being sealed in therebetween. The liquid crystal 150, 250 may
be a negative liquid crystal having a negative dielectric
anisotropy or a positive liquid crystal having a positive
dielectric anisotropy.
[0033] Each display panel 100, 200 also includes a pair of
polarizers 110, 190, 210, 290, a TFT layer 160, 260, black matrix
170, 270, spacers (not shown) and other components built on the
substrates 120, 180, 220, 280. A diffuser 199 may be provided
between the first display panel 100 and the second display panel
200. The diffuser 199, polarizers 110, 190, 210, 290, upper
substrate 120, 220 and lower substrate 180, 280 may be provided as
a sheet or layer.
[0034] The first display panel 100 further includes of a color
filter layer 130 while the second display panel 200 further
includes a contrast filter layer 230 that are sandwiched between
the upper substrate 120, 220 and the lower substrate 180, 280.
[0035] The color filter layer 130 is comprised of a plurality of
color pixels 131 consisting of color sub-pixels 132 configured to
filter a specific color of light, such as red, green or blue. The
color sub-pixel that filters red light, green light and blue light
are referred to as red color sub-pixel, green color sub-pixel and
blue color sub-pixel, respectively. The different colored
sub-pixels repeat along the row of color sub-pixels 132 (See FIG.
4A). A set of adjacent red, green and blue color sub-pixels forms
the color pixel 131 of the first display panel 100. It is
contemplated that the color sub-pixel 132 is not limited to red,
green and blue, and the color pixel 131 may consist of any number
of color sub-pixels 132.
[0036] The contrast filter layer 230 is comprised of contrast
pixels 231 that filter the intensity of light instead of a specific
color of light. Each contrast pixel 231 of the second display panel
200 is configured to provide a specific amount of light to its
corresponding color pixel 131. The number of color pixels 131 in
the first display panel 100 may be equal to the number of contrast
pixels 231 in the second display panel 200, in accordance with an
embodiment of the present disclosure. Since the color pixel 131 is
consist of red, green and blue color sub-pixels 132, the ratio of
the number of color sub-pixels 132 to the number of contrast pixels
231 is 3:1. This ratio may vary depending on the number of color
sub-pixels 132 comprising the color pixel 131.
[0037] As illustrated in FIGS. 4A and 4B, each display panel 100,
200 includes a data line driving circuit 101, 201, a gate line
driving circuit 102, 202, and a timing controller 103, 203 (See
FIG. 5). The driving circuits drive the display panel while the
timing controller controls the driving circuit. The color pixels
131, consisting of color sub-pixels 132.sub.R, 132.sub.G,
132.sub.B, and the contrast pixels 231 are arranged into a matrix
shape in row and column directions. Color sub-pixel 132.sub.R
filters red light, color sub-pixel 132.sub.G filters green light,
and color sub-pixel 132.sub.B filters blue light. Two adjacent data
lines 104, 204 and two adjacent gate lines 105, 205 surround each
color sub-pixel 132 and contrast pixel 231. The gate lines 105, 205
extend in a first direction and the data lines 104, 204 extend in a
second direction. While in FIGS. 4A and 4B, the first direction is
along the X direction and the second direction is along the Y
direction, it should be appreciated that the first and second
directions are not limited to this configuration. It is also
contemplated that the color pixels 131, the color sub-pixels 132,
and the contrast pixels 231 may have non-rectangular shapes.
[0038] Each color sub-pixel 132 and contrast pixel 231 has a
capacitor 136, 236 configured to generate electric field for
controlling the liquid crystal pertaining to that particular pixel.
Said a capacitor 136, 238 is electrically connected to one of the
gate lines 105, 205, a respective one of the data lines 104, 204,
and a common electrode electrical line 137, 237.
[0039] The respective sizes 134, 233 of the color sub-pixel 132 and
the contrast pixel 231 are the area approximately defined by the
adjacent data lines 104, 204 and adjacent gate lines 105, 205. The
size 133 of the color pixel 131 is the sum of the sizes 134.sub.R,
134.sub.G, 134.sub.B of the adjacent color sub-pixels 132.sub.R,
132.sub.G, 132.sub.B, comprising the color pixel 131.
[0040] To produce an image, the light from the backlight unit is
controlled pixel by pixel (or sub-pixel by sub-pixel) by the liquid
crystal. The driving circuits switch the alignment of the liquid
crystal between a state in which the polarized light incident to
the polarizers is rotated by about 90.degree., a state in which the
polarized light is not rotated, and any intermediate states as
desired. A common electrode and a pixel electrode are provided for
each pixel or sub-pixel, applying an electric field to the liquid
crystal. The liquid crystal rotates by dielectric anisotropy
according to the electric field between the common electrode and
the pixel electrode thereby allowing or disallowing light to be
transmitted through the liquid crystal. The TFTs act as switches,
individually controlling the voltage on each pixel or sub-pixel.
The liquid crystal corresponding to a particular pixel or sub-pixel
are controlled so that each pixel displays the appropriate
intensity of color for displaying the desired image. It is
contemplated that the display function of the LCD device may be
achieved using different display modes such as TN (twisted nematic)
mode, VA (vertical alignment) mode, IPS (in-plain switching) mode,
FFS (fringe field switching) mode, and the like.
[0041] Referring to FIGS. 5 and 6, an image processing unit 300
generates a color image data 310 for the first display panel 100
and a contrast image data 320 for the second display panel 200
based on an external input image data 305. The color image data 310
control the color pixels 131 while the contrast image data 320
control the contrast pixels 231. The color image data 310 and the
contrast image data 320 are generated so that the pairs of
corresponding color pixels 131 and contrast pixels 231 filter the
light from the backlight unit 9 (not shown) to form pixels of the
desired image. The color image data 310 may include color values
which dictate the amount of light each color sub-pixel 132 of a
color pixel 131 should filter. Similarly, the contrast image data
320 may include contrast values which dictate the amount of light a
contrast pixel 231 should filter.
[0042] As illustrated in FIG. 6, the image processing unit 300
includes a color image processor 330 and a contrast image processor
340. In particular, the color image processor 330 generates the
color image data 310 and the contrast image processor 340 generates
the contrast image data 320 based on the external input image data
305 received by the image processing unit 300. The image processing
unit 300 then provides the corresponding signals to the data line
driving circuit 101, 201, and the gate line driving circuit 102,
202, of the display panels 100, 200 to produce the desired image
(See FIG. 5).
[0043] In an embodiment of the present disclosure, the size 233 of
the contrast pixels 231 of the second display panel 200 of LCD
device 10 is larger than the size 133 of the color pixels 131 of
the first display panel 100.
[0044] Illustrated in FIG. 7 is the LCD device 10, comprising of
the first display panel 100 and the second display panel 200,
viewed by the person 1 at the distance H from the first display
panel 100. Because of the components of the display panels as well
as other components that are positioned between them, the first
display panel 100 and the second display panel 200 are separated by
a gap D. The gap D may be the distance between the color filter
layer 130 of the first display panel 100 and the contrast filter
layer 230 of the second display panel 200. As a result of the gap
D, the image produced by the second display panel 200 is displaced
from the image produced by the first display panel 100 because the
color pixel 131 does not properly align with its corresponding
contrast pixel 231 when viewed from position 2, said position 2 is
the location of the eyes of person 1 (see FIG. 1). To prevent this
image displacement, the size 233 of the contrast pixels 231 of the
second display panel 200 is larger than the size 133 of the color
pixels 131 of the first display panel 100, in accordance with an
embodiment of the present disclosure.
[0045] As shown in FIGS. 4A, 4B and 7, the color pixel 131 has a
length L.sub.f1 and the contrast pixel 231 has a length L.sub.s1
that extend in the first direction of the gate lines 105, 205
(e.g., the X direction in FIGS. 4A and 4B). Similarly, the color
pixel 131 has a length L.sub.f2 and the contrast pixel 231 has a
length L.sub.s2 that extends in the second direction of the data
lines 104, 204 (e.g., the Y direction in FIGS. 4A and 4B).
[0046] To ensure that color pixel 131 aligns with its corresponding
contrast pixel 231 when viewed from position 2 by person 1 at the
distance H, an angle A.sub.f that the color pixel 131 makes with
position 2 must be the same as an angle A.sub.s that the contrast
pixel 231 makes with position 2 (See FIG. 7). Accordingly, the
ratio of the length L.sub.s1 of the contrast pixel 231 and the
length L.sub.f1 of the color pixel 131 is shown by the following
equation:
Ls 1 Lf 1 = H + D H ( 1 ) ##EQU00001##
[0047] Based on equation (1), the length L.sub.s1 may be expressed
in terms of the length L.sub.f1 as follows:
Ls 1 = H + D H Lf 1 ( 2 ) ##EQU00002##
[0048] It should be appreciated that for the length L.sub.f2 of the
color pixel 131 and the length L.sub.s2 of the contrast pixel 231
extending along the second direction of the data lines 104, 204,
the relationship of the length L.sub.s2 and the length L.sub.f1 is
expressed in the same equation:
Ls 2 = H + D H Lf2 ( 2 ) ##EQU00003##
[0049] Since the gap D may be due to components of the display
panels as well as other components that are positioned between the
first display panel 100 and the second display panel 200, the gap D
may be approximated from the components and materials used in
manufacturing the LCD device 10. As for the distance H, this may be
approximated as the typical distance of the person 1 viewing the
LCD display 10 depending on the use for which the display is
intended.
[0050] In an embodiment of the present disclosure, the length
L.sub.s1, L.sub.s2 of the contrast pixel 231 is within the range of
1.003 to 1.150 times longer than the length L.sub.f1, L.sub.f2 and
of the color pixel 131. Accordingly, the size 233 of the contrast
pixel 231 is within the range of 1.006 to 1.323 times larger than
the size 133 of the color pixel 131. Likewise, the area 211 of the
second display panel 200 is within the range of 1.006 to 1.323
times larger than the area 111 of the first display panel 100 (See
FIG. 2).
[0051] In another embodiment of the present disclosure, the image
processing unit 300 of the LCD device 10 is further comprised of a
control device 350 (See FIG. 6) which switches the image processing
unit 300 to a first mode or a second mode. The image processing
unit 300 generates the contrast image data 320 depending on the
mode it is switched on.
[0052] As illustrated in FIG. 8A, in the first mode, the person 1
views the LCD device 10 from a center position 3, said center
position 3 is the location of the eyes of person 1. In the center
position 3, a line of sight 6 of the person 1 is almost normal to a
center point 7 of the display surface of the first display panel
100 of the LCD device 10. As shown in FIG. 8A, an angle of
incidence A.sub.i of the line of sight 6 is less than 10
degrees.
[0053] In the second mode, the person 1 views the LCD device 10
from a periphery position 4, said periphery position 4 is the
location of the eyes of person 1, as shown in FIG. 8B. In the
periphery position 4, the angle of incidence A.sub.i of the line of
sight 6 is 10 degrees or greater than 10 degrees.
[0054] Under the second mode, the generation of the contrast image
data may include applying an expansion using known method to
account for the periphery position 4 of person 1. This expansion
modifies the resulting contrast image data 320 so that each
contrast pixel 231 provides the correct amount of light to the
color pixel 131 to which the contrast pixel 231 is aligned to with
when viewed from the periphery position 4. Said color pixel 131 to
which the contrast pixel 231 is aligned with is not necessarily its
corresponding color pixel 131. It is contemplated that the
expansion under the second mode may vary depending on the periphery
position 4 of person 1. The amount of expansion applied to the
contrast image data 320 may be based on the angle of incidence
A.sub.i of the line of sight 6 of person 1.
[0055] Under the first mode, no or less expansion is applied. The
contrast image data 320 are generated so that each contrast pixel
231 provides an amount of light with less supplement to its
corresponding color pixel 131.
[0056] Because of the expansion, the image generated by the image
processing unit 300 based on the contrast image data 320 under the
second mode is more blurred than the image generated using the
contrast image data 320 under the first mode.
[0057] In an embodiment of the present disclosure, the control
device 350 may be controlled manually or may automatically adjust
depending on the position 2, said position 2 is the location of the
eyes of person 1. As shown in FIG. 9, the LCD device 10 includes a
sensing device 8 configured to detect the location of the eyes of
person 1. Said sensing device 8 may be a camera. It should be
appreciated that the sensing device is not limited to a camera and
may be any device that can be used to determine the position 2 of
person 1 such as a proximity sensor, laser displacement sensor, or
heat detector.
[0058] Based on the detected position 2 of person 1, the control
device 350 switches to the first mode or the second mode. Using
known method, the angle of incidence A.sub.i of the line of sight 6
of person 1 is measured. The control device may be configured to
switch to the first mode when the angle of incidence A.sub.i of the
line of sight 6 is less than 10 degrees and to the second mode when
the angle of incidence A.sub.i is 10 degrees or greater than 10
degrees.
[0059] Alternatively, the person 1 may manually adjust the control
device 350 to the first mode or the second mode, through an input
unit (not shown), such as on a touch screen or a button.
[0060] In another embodiment of the present disclosure, the LCD
device 10 is further comprised of an adjuster device 400 configured
to change the relative position between the first display panel 100
and the second display panel 200.
[0061] Illustrated in FIG. 10 is the LCD device 10, comprising of
the first display panel 100 and the second display panel 200,
viewed by the person 1 at the distance H from the first display
panel 100. The first display panel 100 is closer to the person 1
than the second display panel 200. Because of the components of the
display panels as well as other components that are positioned
between them, the first display panel 100 and the second display
panel 200 are separated by a gap D. The gap D may be the distance
between the color filter layer 130 of the first display panel 100
and the contrast filter layer 230 of the second display panel 200.
As a result of the gap D, the image produced by the second display
panel 200 is displaced from the image produced by the first display
panel 100 because the color pixel 131 does not properly align with
its corresponding contrast pixel 231 when viewed from position 2,
said position 2 is the location of the eyes of person 1 (see FIG.
1). To prevent this image displacement, the relative position
between the first display panel 100 and the second display panel
200 is changed by the adjuster device 400 based on the position 2
of person 1, in accordance with an embodiment of the present
disclosure.
[0062] As shown in FIG. 10, the adjuster device 400 may change the
relative position of the first display panel 100 and the second
display panel 200 along the plane parallel to the display areas
111, 211 of the display panels. In particular, the adjuster device
400 may change the relative position of the display panels in the
first direction of the gate lines 105, 205 (e.g., the X direction
in FIG. 10) or in the second direction of the data lines 104, 204
(e.g., the Y direction in FIG. 10). The adjuster device 400 may
also change the relative position of the first display panel 100
and the second display panel 200 along the direction parallel to
the gap D (e.g., the Z direction in FIG. 10). This changes the gap
D between the display panels.
[0063] The adjuster device 400 changes the relative position of the
first display panel 100 and the second display panel 200 to ensure
that color pixel 131 aligns with its corresponding contrast pixel
231 when viewed from position 2 by person 1 at the distance H.
[0064] It is contemplated that the adjuster device 400 may be
controlled manually or automatically through a sensing device
configured to detect the location of the eyes of person 1. It
should be appreciated that the sensing device is not limited to a
camera and may be any device that can be used to determine the
position 2 of person 1 such as a laser displacement sensor or a
heat detector.
[0065] Although many subject matters have been specifically
disclosed in the foregoing description, they should be construed as
illustrations of various embodiments rather than a limitation to
the scope of the present disclosure. The present disclosure should
not be limited by the embodiments disclosed herein but should be
determined by the claims and the equivalents thereof.
* * * * *